用UE10／PVA混合体系制备的O／W型生漆乳液的流变性

Rheology of O/W Raw Lacquer Emulsion Prepared by Mixed Emulsifier UE10/PVA

以漆酚基乳化剂(UE10)和聚乙烯醇(PVA)为混合乳化剂制备了水包油(O/W)型生漆乳液(RLE).研究了UE10与PVA的质量比、混合乳化剂浓度(cME)、水与生漆(RL)的质量比、温度和贮存时间对RLE流变性的影响.结果表明,RLE的黏度随着PVA用量的增加而增大;在cME较低时,RLE都有剪切变稀的特性,表现出假塑性流体的行为,其流变曲线能与Casson和Herschel-Bulkley模型良好拟合;当cME≥10.0%,RLE则表现出膨胀型流体的特征,其流变曲线能与Herschel-Bulkley模型良好拟合,不能与Casson模型较好地拟合.RLE的黏度随着贮存时间的增长而增大,但假塑性流体特征未变;RLE的黏度随着温度的升高而降低.

The O/W type raw lacquer emulsion（RLE） was prepared by the mixed emulsifier urushiol-based emulsifier（UE10）/ polyvinyl alcohol（PVA）. The effects of quality ratio of UE10 and PVA ,mixed emulsifier concentration（cME）, quality ratio of water and raw lacquer,temperature and storage time on the rheology of RLE were investigated. The results showed that the viscosity of RLE increased with increasing the PVA content. The shear stress versus shear rate curve of RLE could be well fitted by the Casson and the Herschel-Bulkley models for various quality ratio of UE10 and PVA. At low concentration of mixed emulsifier UE10/PVA （CME） ,RLE belonged to pseudoplastic fluids and the shear stress versus shear rate curve of RLE was well suitable for the Casson and the Herschel-Bulkley models. As CME was increased to no less than 10.0 %, the viscosity of RLE decreased remarkably with increasing shear rate （0-50.0 s^-1 ） ,then increased slowly with increasing shear rate（50.0-250.0 s^-1 ）. RLE belonged to swell fluids and the shear stress versus shear rate curve of RLE could be well fitted by the Herschel-Bulkley model but poorly suitable for the Casson model when cME was increased to no less than 10.0%. The viscosity of RLE increased with the increasing of storage time. The viscosity of the RLE decreased as the temperature was increased.